BACKGROUND: Patients who are categorized with class I obesity have a body mass index (BMI) of 30-34.99 kg/m(2). This population of patients has a predisposition to diabetes, hypertension, and dyslipidemia. The aim of the present study was to investigate the improvements of these co-morbidities in a class I obese population that had undergone a bariatric procedure.METHODS: After internal review board approval and with adherence to the Health Insurance Portability and Accountability Act guidelines, a retrospective review was performed of a prospectively maintained database of 42 class I obese patients who underwent a bariatric procedure at our institution during a 10-year period, from February 2000 to May 2010. The fasting glucose level, glycosylated hemoglobin level, lipid profile, initial weight, and BMI were measured in the preoperative and postoperative periods.RESULTS: Our patient population consisted of 30 women and 12 men, with a preoperative mean BMI of 33.9 kg/m(2). Laparoscopic sleeve gastrectomy was performed in 24 patients (57%), laparoscopic Roux-en-Y gastric bypass in 8 (19%), and laparoscopic adjustable gastric banding in 10 (24%). Of these 42 patients, 25 (60%) had type 2 diabetes, 1 patient was glucose intolerant, 27 (64%) had arterial hypertension, 25 (60%) had dyslipidemia, 17 (40%) had sleep apnea, and 8 (19%) had osteoarthritis. The postoperative findings included a mean BMI of 26.5 kg/m(2) and a mean weight loss of 41.4 lb. Of the 25 diabetic patients, 5 (20%) gained remission and 12 (48%) improvement of their diabetic status. The single patient with glucose intolerance showed improvement. Of the 27 patients with arterial hypertension, 9 (33%) showed remission and 13 (52%) improvement. Dyslipidemia resolved in 5 patients (20%) and improved in 13 (52%). Obstructive sleep apnea resolved in 10 (59%) and improvement was seen in 1 patient (6%). Finally, osteoarthritis resolved in 1 patient (12%) and improved in 5 (63%).CONCLUSION: Bariatric surgery can significantly improve or resolve co-morbid metabolic conditions in patients with class I obesity.